Nice.
Two features worth considering is "Valet mode" - which is basically a permanent disarm and a "Carjack" mode. This could be anything, but I would think of something like. The car starts as though the correct code was entered, but after some time limit and the car is stopped, it will not start again, It would be better to use "not moving" rather than braked.
Valet/shop mode could be different - "Permanent disarm" or "disarm for x days". The "normal" code entered would disarm Valet mode.
So, the thief car jacks you just as your getting into the car and you tell him the code or whatever. He drives for 5 minutes and stops at a light. Car won;t start even with the code that worked.
So, you park the car at a Valet. it gets stolen and e.g. 24 hours later, the car won't start.